Let's simplify step-by-step To understand :)
3x2−7x−(x2+3x−9)
Distribute the Negative Sign:
=3x2−7x+−1(x2+3x−9)
=3x2+−7x+−1x2+−1(3x)+(−1)(−9)
=3x2+−7x+−x2+−3x+9
Combine Like Terms:)
=3x2+−7x+−x2+−3x+9
=(3x2+−x2)+(−7x+−3x)+(9)
=2x2+−10x+9
Answer :)
=2x2−10x+9
HOPE THIS HELPS
Okay, so total dogs are 49.
So we know if x=large dogs and y=small dogs, then x+y=49.
Next we are told that there are 36 MORE small dogs than large dogs. We can take that more meaning addition, and x being our value for large dogs. So y=x+36.
After that we now know what value we can plug in for y. So x+x+36=49.
We can then simplify it to 2x+36=49.
Subtracting the 36 from both sides, leaves you with 2x=13.
Followed by dividing both sides by 2, gives you x=6.5. Or 6.5 large dogs.
Now we can plug this into our formula for the small dogs (y=x+36) to give us y=6.5+36, which simplifies to y=42.5. Or 42.5 small dogs. Which is our answer.
We can double check it by adding the small and large dogs together, 6.5+42.5, which gives us 49, our total entries.
ANSWER
x coordinates of the intersection points
EXPLANATION
The given system of equations is:


We want to use the graph of these functions to solve

The point of the intersection of the graph gives the solution to the simultaneous equation above.
Hence the x-coordinates of the intersection points gives the solution set of

The last choice is correct.